Diamond Tiara's father is Filthy Rich. He first appears in Family Appreciation Day giving a presentation to Diamond Tiara's class about his business, Rich's Barnyard Bargains. He is also a close friend of Granny Smith's and stated to have the selling rights to her first hundred jars of zap apple jam during zap apple harvest season. In the IDW comics story arc Election, Filthy Rich also briefly serves as mayor of Ponyville.
Diamond Tiara's mother is Spoiled Rich; before marrying into the Rich family, her name was Spoiled Milk. She is first indirectly mentioned by Babs Seed in One Bad Apple, and she makes her physical debut in Crusaders of the Lost Mark as the president of the Ponyville school board. Unlike her husband Filthy, Spoiled is very pompous toward lower-class ponies and overbearing in her parenting toward Diamond Tiara.
In Family Appreciation Day, Diamond Tiara's great-grandfather Stinkin' Rich is featured in flashback opening a zap apple jam stand, which later grew into Rich's Barnyard Bargains.